As the Museum prepared for the exhibition’s opening, Lauri Halderman, senior director of exhibition interpretation, spotted the parasite in an unexpected place—carved into the surface of an elephant tusk on display in the Hall of African Peoples.

“I have stopped and looked at that tusk dozens of times over the course of many years,” says Halderman. “It’s a spectacular artifact. But of course that particular detail never before registered. It’s only because we were all working on the Guinea worm exhibition that I noticed it at all.”

The elaborate carving features depictions of Congolese peoples’ suffering at the hands of Portuguese slave traders. But one detail may illustrate healing, albeit of a painful sort. One tableau on the tusk, according to Museum scientists in Invertebrate Zoology and Anthropology, appears to show a Congolese traditional healer extracting a Guinea worm from the foot of a sitting patient while a bystander places a comforting hand on top of the patient’s head—a scene that’s remarkably similar to the way Guinea worm disease is treated today.

With no vaccine for Guinea worm, and no drugs to fight the infection, treatment remains what it has been for centuries: slow and painful removal of the nematode worm as it erupts from the victim’s skin. “This is the only parasite of humans that must cause pain in order to complete its life cycle,” says Mark Siddall, curator in the Division of Invertebrate Zoology who also curated Countdown to Zero. (Visit the exhibition to find out more about The Carter Center’s program, which has helped reduce the number of Guinea worm cases by more than 99 percent since the 1980s—putting this disease on the road to eradication.)

Extracting a Guinea worm is a slow and painful process. Some historians believe the medical symbol known as the Staff of Asclepius was inspired by the age-old method of Guinea worm extraction.

The Museum acquired the carved tusk as part of an exchange from the Liverpool Museum in 1905, according to Curatorial Associate Jacklyn Lacey, who says that the object was likely crafted in the mid-to-late 19th century in the Kingdom of Kongo, which spanned areas that are now the nations of Congo, The Democratic Republic of Congo, and Angola.

Kongo ivories such as this one, says Lacey, were originally created at the behest of Kongo chiefs for courtly use. As ivory became more commodified during the Atlantic slave trade, though, ivories like this one were frequently commissioned for trade in the West. This particular tusk is characteristic of the tradition of Loango Coast ivory souvenir carving, showing a caravan scene of European traders and African porters carved in a cycle that descends down the tusk. Depictions of the cruelty of the slave trade in these encounters were not uncommon, but this piece is notable for being less stylized than contemporary works.

“This carving shows that people in areas with endemic parasitic infections have had traditional medical methods for hundreds of years that include the safest way to extract the Guinea worm parasite while minimizing pain,” says Lacey. “It’s the same winding method that is recommended today.”